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Homework Help: Calc II Partial Fractions with Natural Logs

  1. Sep 25, 2008 #1
    1. The problem statement, all variables and given/known data

    [tex]\int[/tex][tex]\frac{dx}{x(1+ln x)}[/tex]

    2. Relevant equations
    Partial Fractions? Maybe I am solving this wrong...

    3. The attempt at a solution

    [tex]\frac{A}{X}[/tex] + [tex]\frac{B}{1+ln x}[/tex] = 1

    A(1+lnx) + Bx =1
    A + Alnx + Bx =1

    This doesn't seem to work out properly. I have been having a lot of trouble understanding partial fractions so any help in assisting me in making this first step of the problem would be greatly appreciated! Even if partial fractions aren't the correct way to go about this, if you could explain how you knew what to do, I think it would help me a lot in the long run! Thanks!
  2. jcsd
  3. Sep 25, 2008 #2


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    Gold Member

    I dont think you can use partial fractions like that since the integrand is not a rational function.

    Try a substitution, let u=1+ln x
  4. Sep 26, 2008 #3
    let u=lnx
  5. Sep 26, 2008 #4
    ignore me! i was sick :(
  6. Sep 26, 2008 #5


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    Gold Member

    Your sub still works too
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